1. Field of the Invention
The present invention relates to magnetic sensors, and particularly relates to a magnetic sensor including a magnetoresistive element.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 11-274598, Japanese Unexamined Patent Application Publication No. 9-102638, International Publication No. WO 2013/171977, Japanese Unexamined Patent Application Publication No. 2012-88225, and Japanese Unexamined Patent Application Publication No. 2013-250182 disclose magnetic sensors aiming at improvement in magnetic field detection isotropy.
In a magnetic sensor disclosed in Japanese Unexamined Patent Application Publication No. 11-274598, a pattern of a magnetoresistive element has a spiral shape. Both end portions of the spiral pattern are respectively provided in outermost portions on the opposite sides to each other. The pattern of the magnetoresistive element is substantially defined by only a curvature portion.
In a magnetic sensor disclosed in Japanese Unexamined Patent Application Publication No. 9-102638, a magnetoresistive element is spirally wound in a plurality of turns to have a circular shape, and is deposited so as to be isotropic with respect to an external magnetic field.
In a magnetic sensor disclosed in International Publication No. WO 2013/171977, each of a plurality of magnetoresistive elements in a bridge circuit is configured such that a plurality of sections extending along a direction substantially orthogonal to a magnetic field detection direction as a whole are aligned in parallel to each other at a predetermined interval and are joined together so as to be successively folded back, and in each of the plurality of sections, a plurality of portions provided along the magnetic field detection direction are aligned in parallel to each other at a predetermined interval and are joined together so as to be successively folded back, thereby being formed in an electrically-connected zig-zag pattern.
A magnetic sensor disclosed in Japanese Unexamined Patent Application Publication No. 2012-88225 includes two magnetoresistive elements that are connected in parallel, and each of which has a shape in which semicircle arc patterns having different diameters are continuously joined.
In a magnetic sensor disclosed in Japanese Unexamined Patent Application Publication No. 2013-250182, the center of a first sensing section having a regular octagon shape matches the center of a second sensing section having a regular octagon shape, and the first sensing section is arranged in an outer side portion of the second sensing section. A linear layout of a second magnetoresistive element of the second sensing section is slanted by 22.5 degrees relative to a linear layout of a first magnetoresistive element of the first sensing section.
It is not described explicitly or implicitly in Japanese Unexamined Patent Application Publication No. 11-274598 and Japanese Unexamined Patent Application Publication No. 9-102638 to configure a magnetic sensor by using a plurality of magnetoresistive elements. There is still room for improvement in magnetic field detection isotropy of the magnetic sensors disclosed in International Publication No. WO 2013/171977, Japanese Unexamined Patent Application Publication No. 2012-88225, and Japanese Unexamined Patent Application Publication No. 2013-250182.